1. Field of the Invention
This invention relates to conduit cleaning systems, and especially to a permanently-installed electric-pump and water-pressure powered beer coil and conduit cleaner.
2. Description of the Prior Art
The usual beverage delivery system comprises a source of the beverage, for example a keg of draft beer, a source of pressure, for example a container of compressed carbon dioxide, and a conduit to carry the beverage to a discharge point having a manually activated spigot. In order to discharge a beverage at an appropriate temperature for drinking, the beverage source may be stored in a temperature-controlled area, or the beverage-carrying tube may be passed through such an area, thereby bringing the beverage to desired temperature. In taverns, the system frequently takes the form of a refrigerated room for storage of kegs, and a system of permanent tubes or conduits for connecting the kegs to distribution spigots at a customer service area.
Draft beer is an upasteurized food material which is surprisingly sensitive to rough handling. Discontinuities in pressure and temperature encountered in a conduit by the beer may cause unacceptable foaming, and may adversely affect the taste and aroma. Foreign material must also be strictly avoided. During brewing, the brewmaster, of course, has various means of controlling the chemical and physical environment of the processed materials. In order to ensure correct taste, aroma and appearance, similar care must be taken with the beverage delivery system.
Care must be taken to maintain the optimum taste, aroma and appearance; and moreover, safe and correct sanitation requires that the beverage delivery system be as clean as possible. Under some circumstances, the organic materials present in the beer mmay chemically react or decompose. So-called beer stones may precipitate out in the conduit system. Microbial action can degrade the beer. Therefore, for many reasons, the conduit must be kept scrupulously clean.
A frequently encountered beverage delivery system relying on heat exchanged delivery employs a heat transfer section along the beverage delivery conduit, which heat transfer section is located in a refrigerated area. The kegs may or may not also be kept refrigerated. Relatively warmer beer from a keg is conveyed along a conduit to the heat transfer passage, immediately preceding the spigot. It will be appreciated that the heat transfer section, which normally takes the form of a helical coil of metal tubing, is both a physical discontinuity and a temperature discontinuity encountered by the beverage being coveyed through the conduit.
Beverage delivery systems employing heat transfer coils are more susceptible to accumulations of unwanted materials and are less easily cleaned than are simple conduit sections of systems in which the kegs themselves are stored in a temperature controlled area. Nevertheless, both types of beverage delivery systems must be regularly cleaned both to produce a good beverage and to comply with relevant health codes.
Conduits may be cleaned by flushing with cleaning fluid and water. In early conduit cleaning systems water pressure was used to fill the tubes with water, and then a manually reciprocating pump device was operated to surge and agitate the water together with a cleaning solution, thereby dissolving and/or loosening foreign materials. The conduits are then opened at the keg and gravity drained. U.S. Pat. Nos. 1,993,371 to Jones; 2,023,854 to Petricone; 2,078,740 to Stahl; and No. 2,092,257 to Lewis involve such devices.
In order to function, pump-driven agitation devices of employ either a circular path around which the fluid is agitated, or a substantial length of tube must be involved such that a surging flow can be accommodated at least in a section of the tube. The aforesaid patents to Jones, Petricone and Lewis teach cleaning a pair of adjacent beverage delivery tubes at the same time by connecting them in a loop. The beverage tubes are removed from the kegs and manually connnected together at their keg ends; and, the pump is moved in and connected between the distribution spigots at opposite ends of the two tubes being cleaned. A third connection to a source of water may be added whereby the flushing system is initially charged with water, after which the user manually or electrically operates the pump to force the water around the circular passage created by the connection of conduits at the keg end and through the pump. These multiple connections present a danger of spillage which is a serious problem in the customer service area as well as in the refrigerated storage area. Such connections likewise do not lend themselves to quick or convenient operation.
The cleaning device of Stahl is somewhat more simple in that the manually-operated pump functions on a first stroke to draw cleaning fluid into the pump chamber, and on a second stroke to discharge the pump fluid into the beverage coil conduit. The fluid is alternately surged into the beverage coil and drawn back into the pump, finally being discharged into a reservoir. The spigot may be opened during cleaning. Should the device be applied to a closed conduit, a substantial conduit length may be necessary before the surging on which this system depends will occur. Moreover, in such system, for the most part, the surging occurs only in a portion of the conduit close to the pump.
U.S. Pat. Nos. 2,092,257 to Lewis; 2,906,435 to Nichols; and 3,441,034 to Burks employ pumps in an effort to provide the necessary surging of fluid to clean the tubes. Similarly, U.S. Pat. Nos. 2,458,230, Warcup and 2,645,379 to Audia appear to rely upon fluid pressure and/or air pressure to achieve cleaning fluid motion. In Lewis, fluid motion is assisted by connecting neighboring keg lead lines together, forming a loop. A number of the subsequent devices include manually-operated valves adjacent the keg or the spigot.
Typically, the prior art coil cleaning systems are add-on devices which are temporarily installed by removing fitting from kegs and attaching cleaning system tubes to the conduits at the kegs and/or spigots and/or at a water supply. It has been proposed in a previous application by the present applicant, copending herewith, to adapt a system such that a cleaning system could be a permanently-installed part of the conduit plumbing fixtures of a tavern or like establishment. Basically, a system of valves and pumps is disposed to clean a system of closed conduits (i.e., with closed spigots) downstream in the flow path from a permanent cleaning apparatus. A separate provision was provided for cleaning the so-called "lead beverage tubes," that is, the tubes between the kegs and the permanently-installed cleaning apparatus located near the keg end of the conduits.
Current commercial beverage distribution systems rely upon standardized fittings for connection of compressed gas such as CO.sub.2 or compressed air, and to convey the beverage along the conduit system. In permanent-plumbing installations, the lead beverage tube is a flexible tube adapted to connect a keg at any location within a certain span, to the conduit system. A standardized fitting is used in the Tri Tap dispensing system of Draft Systems, Inc, 19791 Bahama Street, Northridge, Calif. 91324 (213-882-8012). Such fittings may be connected to kegs to include not only a supply for the beverage conduit and a supply of compressed gas, but also to isolate the conduit and/or key upon disconnection. A system of integral valves is included such that upon removing the fitting from the keg, appropriate valve closures are initiated to avoid the possible contamination of the beverage, loss of compressed gas and the like.
Efforts have been made to adapt the Tri Tap system to accomplish cleaning of multiple beverage tubes by fittings adapted to connect the tubes in a single length. Basically, a plumbing union having an axial rod for operating the valves in the standardized keg fitting facilitates interconnection of two such keg fittings and opens their internal valves to flow.
The present invention derives the benefits of a permanently-installed beverage cleaning system, without the necessity of a separate cleaning apparatus for the lead beverage tubes. This is accomplished by adapting the permanently-installed system with permanently-installed unions of the aforesaid connection variety, such that the entire length of beverage tube conduit can be cleaned right on the permanent apparatus, using a automatic sequence-controlling device to control operation of valves and a pump. The kegs are disconnected and the conduits isolated by removing the standard fittings from the kegs for attachment to one another. Upon operation of the cleaning system, the contents of the conduits are cleaned and drained under control.